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Copolymer Nanoparticles (copolymer + nanoparticle)

Distribution by Scientific Domains
Polymers and Materials Science75%
Chemistry25%

Kinds of Copolymer Nanoparticles

  • block copolymer nanoparticle
    		•

    Selected Abstracts

    Amphiphilic Block Copolymers Bearing Ortho Ester Side-Chains: pH-Dependent Hydrolysis and Self-Assembly in Water

    MACROMOLECULAR BIOSCIENCE, Issue 2 2010
    Rupei Tang
    Abstract A new type of pH-responsive block copolymer nanoparticle has been synthesized and characterized. The amphiphilic diblock copolymer, PEG- b -PMYM, contains acid-labile ortho ester side-chains in the hydrophobic block and can self-assemble into micelle-like nanoparticles in water at neutral pH. Hydrolysis of the ortho ester side-chains follows a distinct exocyclic mechanism and shows pH-dependent kinetics, which triggers changes in nanoparticle size and morphology. The nanoparticles have been found to be non-toxic to cells in vitro. The ability to tune the size and morphology of biocompatible block copolymer nanoparticles by controlling the pH-sensitive side-chain hydrolysis represents a unique approach that may be exploited to improve the efficacy of nanometer-scale drug delivery. [source]

    Complete high-density lipoproteins in nanoparticle corona

    FEBS JOURNAL, Issue 12 2009
    Erik Hellstrand
    In a biological environment, nanoparticles immediately become covered by an evolving corona of biomolecules, which gives a biological identity to the nanoparticle and determines its biological impact and fate. Previous efforts at describing the corona have concerned only its protein content. Here, for the first time, we show, using size exclusion chromatography, NMR, and pull-down experiments, that copolymer nanoparticles bind cholesterol, triglycerides and phospholipids from human plasma, and that the binding reaches saturation. The lipid and protein binding patterns correspond closely with the composition of high-density lipoprotein (HDL). By using fractionated lipoproteins, we show that HDL binds to copolymer nanoparticles with much higher specificity than other lipoproteins, probably mediated by apolipoprotein A-I. Together with the previously identified protein binding patterns in the corona, our results imply that copolymer nanoparticles bind complete HDL complexes, and may be recognized by living systems as HDL complexes, opening up these transport pathways to nanoparticles. Apolipoproteins have been identified as binding to many other nanoparticles, suggesting that lipid and lipoprotein binding is a general feature of nanoparticles under physiological conditions. [source]

    Preparation and in vitro release of D,L -tetrahydropalmatine-loaded graft copolymer nanoparticles

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008
    Yinglei Zhai
    Abstract D,L -tetrahydropalmatine (THP)-loaded poly{[,-maleic anhydride-,-methoxy-poly(ethylene glycol)]- co -(ethy cyanoacrylate)} (PEGECA) amphiphilic graft copolymer nanoparticles (PEGECAT NPs) were prepared by the nanoprecipitation technique. The effects of solvent property, temperature, copolymer composition, and drug feeding on the drug-loaded amount and size of PEGECAT NPs were investigated. The morphological structure of PEGECAT NPs was characterized by transmission electron microscopy (TEM), proton nuclear magnetic resonance (1H NMR), and the size was measured by laser particle size analyzer (LPSA). In vitro release behaviors of drug from PEGECAT NPs were examined by high-pressure liquid chromatography (HPLC). The results demonstrate that PEGECAT NPs take on a spherical morphology with an inner core and outer shell before and after in vitro release. THP can be incorporated into the hydrophobic core of PEGECAT NPs and the drug-loaded amount is higher than 5%. The release of THP from PEGECAT NPs is initially fast and then slows down. The accumulated release is lower than 40% after 48 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

    Biofunctionalized block copolymer nanoparticles based on ring-opening metathesis polymerization

    JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2006
    Alvaro Carrillo
    Abstract We present an approach to the synthesis of biofunctionalized block copolymer nanoparticles based on ring-opening metathesis polymerization; these nanoparticles may serve as novel scaffolds for the multivalent display of ligands. The nanoparticles are formed by the self-assembly of diblock copolymers composed of a hydrophobic block and a hydrophilic activated block that can be functionalized with thiolated ligands in aqueous media. The activated block enables control over the orientation of the displayed ligands, which may be sugars, peptides, or proteins engineered to contain cysteine residues at suitable locations. The nanoparticle diameter can be varied over a wide range through changes in the composition of the block copolymer, and biofunctionalization of the nanoparticles has been demonstrated by the attachment of a peptide previously shown to inhibit the assembly of anthrax toxin. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 928,939, 2006 [source]

    Amphiphilic Block Copolymers Bearing Ortho Ester Side-Chains: pH-Dependent Hydrolysis and Self-Assembly in Water

    MACROMOLECULAR BIOSCIENCE, Issue 2 2010
    Rupei Tang
    Abstract A new type of pH-responsive block copolymer nanoparticle has been synthesized and characterized. The amphiphilic diblock copolymer, PEG- b -PMYM, contains acid-labile ortho ester side-chains in the hydrophobic block and can self-assemble into micelle-like nanoparticles in water at neutral pH. Hydrolysis of the ortho ester side-chains follows a distinct exocyclic mechanism and shows pH-dependent kinetics, which triggers changes in nanoparticle size and morphology. The nanoparticles have been found to be non-toxic to cells in vitro. The ability to tune the size and morphology of biocompatible block copolymer nanoparticles by controlling the pH-sensitive side-chain hydrolysis represents a unique approach that may be exploited to improve the efficacy of nanometer-scale drug delivery. [source]

    Development and validation of a high-performance liquid chromatography method for the simultaneous determination of aspirin and folic acid from nano-particulate systems

    BIOMEDICAL CHROMATOGRAPHY, Issue 9 2010
    Abhishek Chaudhary
    Abstract Attention has shifted from the treatment of colorectal cancer (CRC) to chemoprevention using aspirin and folic acid as agents capable of preventing the onset of colon cancer. However, no sensitive analytical method exists to simultaneously quantify the two drugs when released from polymer-based nanoparticles. Thus, a rapid, highly sensitive method of high-performance liquid chromatography analysis to simultaneously detect low quantities of aspirin (hydrolyzed to salicylic acid, the active moiety) and folic acid released from biodegradable polylactide-co-glycolide (PLGA) copolymer nanoparticles was developed. Analysis was done on a reversed-phase C18 column using a photodiode array detector at wavelengths of 233,nm (salicylic acid) and 277,nm (folic acid). The mobile phase consisted of acetonitrile,0.1% trifluoroacetic acid mixture programmed for a 30,min gradient elution analysis. In the range of 0.1,100,,g/mL, the assay showed good linearity for salicylic acid (R2 = 0.9996) and folic acid (R2 = 0.9998). The method demonstrated good reproducibility, intra- and inter-day precision and accuracy (99.67, 100.1%) and low values of detection (0.03, 0.01,,g/mL) and quantitation (0.1 and 0.05,,g/mL) for salicylic acid and folic acid, respectively. The suitability of the method was demonstrated by simultaneously determining salicylic acid and folic acid released from PLGA nanoparticles. Copyright © 2009 John Wiley & Sons, Ltd. [source]